On the use of the Hα spectral line to determine the electron density in a microwave (2.45GHz) plasma torch at atmospheric pressure

The electron density of an argon microwave (2.45 GHz) plasma flame generated at atmospheric pressure has been determined by using the Stark broadening of the experimentally measured H-alpha line emitted by the discharge. The H-beta line was not observable under the experimental conditions of this discharge. Two methods have been employed to obtain the electron density from the Stark broadening of the H-alpha line. The first used the Gigosos-Cardenoso computational model that considers the strong broadening of the H. line by ionic dynamics. Alternatively, a second method based on a calibration of Stark broadenings of H-alpha and H-beta lines offered a simpler way to obtain the electron density. (c) 2006 Elseviei B.V. All rights reserved.